Optical communications are typically implemented by transmitting data through fiber-optic links because light is less prone to optical dispersion through fiber-optic links as opposed to other mediums, such as air. These optical communications use light to convey data to an intended receiver through the fiber-optic link, through “on-off keying” of the wavelength. For example, a binary signal (i.e., a signal of logical 1's and logical 0's) is transmitted through a fiber-optic link with the light switching on and off.
Demand on communications has dictated that optical fiber be shared among users. One method of sharing involves assigning specific time periods to individual users and is called Time Division Multiplexing (“TDM”). During a period of time in TDM, a single user transmits data and other users wait for their time period. Another method of sharing involves assigning specific wavelengths of light to individual users and is called Wavelength Division Multiplexing (“WDM”). In WDM, each user has a specific wavelength of light and may transmit data on that wavelength at any time, but no other user may use that wavelength. Optical Code Division Multiple Access (“OCDMA”) is yet another method to share the optical fiber among a number of users. In OCDMA, each user is assigned a unique code that is composed of temporal and wavelength components. This unique OCDMA signature may be thought of as a unique identifier or thumbprint on a data stream. For a user to receive a data stream, the user must detect a data stream having an appropriate OCDMA signature.
As with other forms of communications, such as radio frequency communications, it is often preferable to encrypt data being transmitted to maintain data privacy. In optical communications, data is typically encrypted in the electronic realm prior to optical transmission in order to achieve data privacy. Once encrypted, the data may be optically transmitted using one of the methods discussed hereinabove. Encryption in the electronic realm, however, often introduces a bottleneck (i.e., a communication slowdown) to the transmission of data because, among other reasons, electronic switching speeds are simply slower than optical transmission speeds.